Windows 7: sims 3 dell inspirion 15r special edition

Hi, I brouight a brand new dell inspirion 15r special edition and downgraded the software to windows 7 from windows 8. and installed most of the sims 3 expansion packs along with some custom content, I was playing the game, building a house and half way through the house, It suddenly crashed, I tried to play it another time but it still froze in the exact same place, i am wondering why my computer crashed after we installed windows 7 and all the expansion packs for the sims


Laptop Specs

Processor

• 3rd Generation Intel® Core™ i5-3210M processor (3M Cache, up to 3.1 GHz)
• 3rd Generation Intel® Core™ i7-3632QM processor (6M Cache, up to 3.2 GHz)

Operating SystemHelp Me Choose

• Windows 8, English (64bit)
• Windows 8 Pro, English (64bit)

Memory5

• 4GB 1 DIMM (4GB x1) DDR3 1600Mhz
• 8GB 2 DIMM (4GB x2) DDR3 1600Mhz

Chipset

• Mobile Intel® 7 Series Express Chipset (HM77)

Video Card

• AMD Radeon™ HD 7730M DDR3 2GB

Display

• 15.6" HD WLED True-Life (1366x768)
• 15.6" FHD Anti-glare (1920x1080)

Audio and Speakers

• Waves MaxxAudio 4.0 studio-quality sound suite + Skullcandy Speakers (2x 2W)

Hard Drive

• Up to 1000GB6 SATA hard drive (5400RPM)

Optical Drive

• 8x DVD+/-RW (standard)
  Blu-ray Disc™ combo (reads Blu-ray Disc™ & writes to CD/DVD) (optional)

Power

• 6-cell 48WHr Li-Ion Battery
  90W AC Power Adapter (standard)

Camera

• Native HD 1.0 MP webcam with digital microphone

Wireless

• Wi-Fi Bluetooth Options:
  Intel® Centrino® Wireless-N 2230 + BT 4.0
  
  Wired communications
  Integrated ethernet 10/100/1000

Ports, Slots & Chassis

• Color, Material & Finish:
  Anodized Aluminum in Stealth Black with precision-etched honeycomb design.
  
  Keyboard:
  Standard full size, optional backlit keyboard
  
  
  
  Externally Accessible
  (3) USB 3.0 + (1) USB 3.0 PowerShare
  RJ45 Ethernet
  HDMI™ v1.4a
  VGA
  Headphone jack
  Microphone jack
  Kensington Security Lock
  AC Power In
  Multi-media Card Reader
  Digital (SD) Memory Card
  Secure Digital High Capacity (SDHC)
  Secure Digital Extended Capacity (SDXC) with UHS 50MB/Sec
  Memory Stick (MS)
  Memory Stick PRO (MS Pro)
  Memory Stick XC (MSXC)
  Multi Media Card (MMC)
  Multi Media Card plus (MMC+) Supported in MMC compatibility mode only
  Dimensions & Weight
  Height: 30.3mm - 34.1mm (1.19” – 1.34”)
  Width: 378 mm (14.88”)
  Depth: 252 mm (9.92”)
  Starting weight: 2.766 kg (6.098lbs)

I'd go for Windows 8 64-bit if your just a gamer or I'll just go for Windows 8 Pro if you use your laptop for home,business,or school.